You won't be disappointed with Collinite 845. I'm a huge fan of the Jescar Powerlock as well. Great sealant.
If it didn't feel slippery, it might be your soap. What are you using for that?
Blue correl or any big gallon size jug of suds specifically for cars ,,, but No wax added.
However I ALWAYS pressure wash ( at a safe distance , water only ) to get the grit off in hopes of less scratching when hand washing with a big ole sponge. I may go to hell for using a sponge , I know sorry .
Would this regular pressure washing have an effect on my wax job durability ? It might I dunno.
Thanks for any tips or pointers